Boiler construction



Jan. r28, 1930. M. v. MILTON BOILER CONSTRUCTION Filed Jan. 24, 1927 2 Sheets-Sheet le FIG@ INVENTOR IWON'rArUrfA/.wnLToN FIG ATI

Jan. 28, 1930. M. v. MILTON 1,745,308

BOILER CONSTRUCTION Filed Jan. 24, 1927 2 Sheets-Sheet 2 INVENTOR MONTAG!! EM MILTON www .ATTOR Patented J an. 28, 1930 `P ATEN T OF F ICE `BOILER' CONSTRUCTION Applicationfiled4 January 24, 1927. Serial No. 163,280.

This invention relates to newand useful iinprovements in boilers and particularlylocomotive boilers, and the objectof the invention is to providel a boiler which will have `a better circulation of water within the boiler and also over the iirebox, and a higher firebox temperature than the boilers at present in use.

`Anotherobject is to provide a boilerhaving means for preheating the air used for combus tion, thereby decreasing the density of smoke from the stack.

A further `object is to provide means to facilitate removal of chemicals liberated by raising the temperature of the water 'by positively guiding them towards the front of the boiler where they may be removed by the use of blow-off valves and the like.

A still further object is to provide a boiler which when compared with the types of boilers at present in use, will be less costly to maintain in proper repair.

A still further obj ect is to provide a boiler having more flexible water legs than usually found in boilers in this class.

A still further object is to provide a firebox which will be simple to construct and easily kept in repair.

` In my invention I accomplish the above objects by forming a water circulating channel in each side of the firebox. The outside of the flreboX is provided with perforations and spaced from said outside is the lining which may be constructed of fire brick, which rests on the foundation ring which also supports the grate. Air passingbetweenthe outside plates and the lining is deflected so that it passes under the grate and through the grate bars to assist in complete combustion of the fuel. The front end of the fireboX is spaced from the end of the boiler and a water circulating channel is formed therein. rIhe side water circulating channels terminate in the blowpf pit between the crown sheet andthe vertically disposed sheet enclosing the pit, and slope downwardly away from the front of the iirebox. The fire brick lining is so formed that it may be easily removed for repairs and the like.

In the drawings which illustratemy invention;

Figure 1 is a partial side elevation of a boiler of the locomotive type showing the irebox.

Figure 2 is af sectional end elevation taken on the line 2-2 Figure 1.

Figure 3 is a sectional end elevation taken 55 on the line 3-3 Figure 1.

Figure 4 is an enlarged sectional plan of one corner of the irebox and partsadjacent thereto, taken on the line 4.-4 Figure 1.

Figure 5 is an-enlarged sectional plan of 60 one corner of the fireboX taken on the line 5--5 Figure 1.

Figure 6 is an enlarged sectional sideelevation'of the boiler taken near the tube sheet.

Figure 7 is an enlarged sectional end ele- 65 vation of one side of the lfire boX taken 1tohrough the approximate centre of the firey Figure` 8 isa partialplan view of theinud ring.

Referring morejparticularly to the drawings, 11 `designates the part of the shell of the boiler which surrounds the firebox 12. Spaced from the shell and forming the upper part of the iirebox is the rebox crown sheet f5 13, the lower edges of which have grooves 14 pressed therein to form water circulating channels. The crown sheet is secured to that part of the plate 11 which forms the outer wall l5 of the rebox. .The outer wall 15 yis 80 provided with Va plurality of perforations 16. Secured to the lower edges of the wall 15 is the foundationring 17, lwhich is provided with recesses 18 spaced from one another and forming inlets for the passage of air into the firebox, in the manner hereinafter de` scribed. The ring 17 supports the grate bars 19 and alsothefire-box lining or wall 20, the outer surface of which is spaced from the inner face of the side walls, and forms a 9G preheating space for the air supplied to the firebox. The channels for the water slope downwardly from the front to the rear plate 21 of the boiler. The channels'are formed by pressing the plate inwardly towards the flreboX forming convex surfaces against the face of which the upper row of bricks of the box lining fit snugly to forma locking means for holding the remaining part of the walls in position. The upper ,edges 22 of said 100 upper row of bricks are bevelled so that when drawn towards the outer wall of the firebox by means of the bolts 28, they will wedge themselves into place and press the lowernost rows of bricks against the ring and against the packing strip 24, which may extend upwardly against the outer face of the lining and bent outwardly to meet the lower edges of the crown sheet in proximity to the pomt where it meets the furnace walls. The front plate 2G provided with a lire door opening 27 and into said opening is placed the ring 28, the inner edge 29 of which is flanged as shown. The ring 28 is secured te one flange 30 of an angle iron ring 3l, the other flange 31a of which is secured to the outer face of the plate 26. Spaced from the inner surface of the front plate is the firebrick lining 32, the lower edge 33 of which rests on the ring 17 and is held in place in a similar manner to the lining of the sides of the box, that is, the upper row 34 of the bricks contact with the convex face 35 of the water channel plate 36, bolts being passed through the bricks in the upper row and through the front fire plate to hold the said b 1 bricks in position. There is a water space between the outer front plate 26 and the inner plate 37 of the firebox and the lower edge 38 of said plate is bent outwardly to meet said plate 26 at a point above the rebox opening. The plate 37 is bent outwardly as at 39 to form a water channel, the ends 40 of which communicate with the upper ends 41 of the water channels at the side of the boiler. The lower ends 42 of the side water channel communicates with a mud pit 43 formed between the throat sheet 44 and the lower end of the tube sheet. Suitable blowol' cocks, not shown, may be fitted to this part of the boiler to clear same of any obstructions and of any of the chemical deposits released from the water through the raising of the temperature of same. A deflector plate 45 may be secured to the lower edge of the outer side walls of the firebox to direct the air passing between the side walls of the firebox toward the underside of the grate bars and u i through the fuel bed. The sides of the rebox may be held in place by the stay bolts 46.

In operation the heat from the fuel in the rebox im Jinges on the crown sheet of the firebox and the maximum heat strikes the .water circulating channel plates and their convex surfaces, setting up a rapid circulation of the water in the channels. The water being rapidly raised in temperature to the point of precipitation releases the chemicals and solids within the water and same flow downwardly towards the blow-out pit in proximity to the bottom of the tube plate of the boiler. The steep angle at which the channels are set assists the solids to flow towards the pit, where they may be removed from the boiler by any of the well-known means. The

air fed to the rebox passes through between the outer plates of the firebox and the lining and is thus preheated by coming in contact with the heated surface of the lining before it is fed into the fireboX, deflectors being provided to facilitate this feature. The inflow of air is shown by the arrows in Figure 7. By pre-heating the air, more complete combustion of the fuel is obtained and therefore higher irebox temperature and therefore increased circulation over the firebox area. The pre-heatin of the air also reduces the density of the smoe from the smoke stack. The life of the lirebox is increased due to the elimination of the usual lower water leg, protection of the outer plate of the firebox by the air space and the lire brick, and the increased circulation in the water chamber surrounding the upper part or roof plate of the rebox.

The maintenance of the lirebox is decreased when compared with the type of irebox at present in use, as the fire brick in the walls may be easily and quickly removed for repairs, and the like, by removing the lock o ts.

Having thus described my invention, what I claim is l. In boiler construction, a firebox having a metallic crown sheet, perforated metallic side walls, lire brick walls spaced from the side walls forming an air space between them, said brick walls extending from the front to the rear of the firebox, and the upper edge of the brick walls sloping downwardly towards the rear of the firebox, means secured to the lower edges of the side walls for supporting the brick walls and the grate of the irebox, means formed in the supporting means and communicating with the air space to allow air to pass through into the lirebox from the air space, means secured to the lower edge of the metallic side walls for deflecting the air towards the arca above the grate, and. water channels, formed by pressing portions of the crown sheet inwardly towards thc interior of the firebox, said water channels being adapted to align with the upper edges of the brick walls and in proximity to the junction between the crown sheet and the metallic side plates.

2. In boiler construction, a. lirebox having a crown sheet, perforated metallic side plates and fire brick side walls spaced from the metallic side plates, the upper edge of said lire brick walls sloping downwardly from front to rear of the firebox, water channels formed in the metallic crown sheet and sloping downwardly from front to rear of the lirebox, and in close proximity to the upper edge of the brick wall, said crown sheet being joined to the metallic side plates in proximity to the upper edge of the brick walls, means secured to the lower edges of the metallic side walls to form a support for the brick walls, said means having passages therein for air passing from the air space between'the walls into the irebox, means for deflecting the air from the air space towards the tirebox and a water channel formed in the front ot the firebox and communicating with the boiler| and the side channels aforementioned.

3. In boiler construction a lirebox having a crown sheet and front plate, side walls ot' metal having perforations formed therein, walls of tirebrick spaced from the metallic side walls and the back of the boiler in proximity to the tire door, the upper edges of the side walls of ire brick sloping downwardly from the front to rear of the Firebox, means secured to the metallic sides to support the brick walls and a lire grate, air passageways formed in the supporting means antl communicating with the air spaces between the metallic and the brick walls, water channels formed in the crown sheet and in the front plate of the iirebox and communicating with each other, said water channels being adapted to overlie the upper edges of the brick walls and project outwardly therefrom, means for securing the crown sheet in proximity to said upper edges of the brick side walls, and deflectors secured to the lower edges of the lnetallic sides to guide air from the air space towards the irebox interior.

4E. A device according to claim 3 having the water channels Yformed by pressing grooves in the crown sheet and front end plate of the irebox.

5. In boiler construction, a irebox, having a crown sheet and a front plate with water channels pressed therein, said water channels being of curved formation and projecting inwardly towards the centre of the irebox, the channels of the crown sheet being 'formed sloping downwardly from front to rear of the firebox, perforated metallic side plates for the lirebox, tire brick side walls spaced from the metallic side plates and resting on supporting means secured to the lower edges of the side plate, air passageways formed in the supporting means and communicating with the spaces between the metallic and brick side walls, the upper edges of said walls being made parallel to and in Jfrictional contact with the water channel walls of the crown sheet, means for securing the crown sheet to the side plates in proximity to the upper edge of the brick walls, the upper rows of which are formed ot' wedge-shaped bricks, means for pulling the wedge-shaped bricks into contact with the walls of the water channel to hold the walls in place, and detlectors secured to the lower edges of the metallic side walls to guide the air from the air space between the side walls towards the lire box.

6. A boiler construction comprising outer metal casing walls, a crown sheet having its lower edge portion secured to the side casing walls and bulged inwardly from said walls to provide water legs sloping downwardly at a steep angle from the Jfront to the rear of the ire box, a front plate having a transverse water leg pressed therein and communicating with the water legs of the crown sheet and with the boiler, a mud pit provided at the lower ends of the water legs formed in said crown sheet, a mud ring secured in said iire box, fire brick walls wedged between the mnd ring and the water legs Jormed in the crown sheet and spaced from the side casing walls of the boiler to provide intervening air chambers to which air is admitted via suitable openings formed in said side casing walls, said mud ring being provided with recesses through which the air admitted to said chambers is permitted to escape below the lower edge ot the mud ring and detlectors positioned below the mnd ring to deflect the escaping air inwardly toward the fire box.

In witness whereof, I have hereunto set my hand.

MONTAGUE V. MILTON. 

